There has been disclosed an example of a sheet separating apparatus. This sheet separating apparatus has a stacking unit, a separation roller, and a separation piece. The stacking unit has a sheet supporting surface capable of supporting a plurality of sheets stacked. The separation roller rotates around a first shaft center parallel to the width direction of the sheet supporting surface, thereby coming into contact with a sheet fed from the stacking unit and conveying the sheet to the downstream side in a conveyance direction perpendicular to the width direction. The separation piece faces the separation roller, and separates sheets one at a time in cooperation with the separation roller.
However, in the above-described related-art sheet separating apparatus, according to whether the number of sheet stacked on the sheet supporting surface is large or small, a trajectory of the leading end of the sheet fed from the stacking unit to the separation roller may be likely to significantly vary. For example, in the related-art sheet separating apparatus, as will be described below, according to whether the number of sheet stacked on the sheet supporting surface is large or small, the sheet separating apparatus may not reliably separate the sheets one at a time.
For example, it is assumed that the separation roller is provided to be able to contact each sheet which is fed from the stacking unit, from a side that is opposite to a side facing the sheet supporting surface, such that the uppermost sheet of the sheets supported on the sheet supporting surface is fed to the separation roller. A nip position is defined as a position where a sheet is nipped by the separation roller and the separation piece when the sheet is fed.
In this case, if the number of sheets stacked on the sheet supporting surface is large, the trajectory of the leading end of the uppermost sheet passes a position close to the separation roller and proceeds toward the nip position. Therefore, the leading end of the corresponding sheet easily reaches the nip position. However, in this case, simultaneous conveyance of sheets may occur. Meanwhile, if the number of sheets stacked on the sheet supporting surface is small, the trajectory of the leading end of the uppermost sheet passes a position separated from the separation roller and close to the separation piece, and proceeds toward the nip position. Therefore, the leading end of the corresponding sheet may be unlikely to reach the nip position. In this case, failure of sheet conveyance may occur.
Also, the sheet separating apparatus is required to be reduced in size.